Network service providers have begun using pseudowires to provide advanced network services to customers. In general, a pseudowire is a term for a service that emulates a native service over a packet switched network such as an IP network, an MPLS network, or a Layer Two Tunneling Protocol (L2TP) network. Native services that are typically emulated via a pseudowire include ATM, Frame Relay, Ethernet, TDM, and SONET/SDH. In one key application, pseudowires allow different types of legacy services to be seamlessly provided across a single packet network. Pseudowires are commonly used within a service provider network to communicate legacy traffic between service provider edge devices. More recently, pseudowires are being used to connect customer edge devices and service provider edge devices. For example, a customer edge device such as a cellular network end station (e.g., a 3G Base Transceiver Station (BTS) or NodeB) may utilize a few pseudowires to emulate TDM, ATM, and/or Ethernet services between the customer edge device and a service provider edge device.
The implementation of a pseudowire typically involves establishing label switched paths (LSPs) or tunnels that are identified by a unique identifier, commonly referred to as a label. In order to establish a pseudowire between two network nodes, pseudowire configuration information, including label numbers, must be communicated between the nodes. Conventional protocols used to configure pseudowires include the Label Distribution Protocol (LDP) and the Resource Reservation Protocol (RSVP). LDP and RSVP are resilient protocols that utilize the Transmission Control Protocol (TCP) at the Transport Layer to ensure reliability of message transmission. Although LDP and RSVP work well to enable the configuration of pseudowires, implementing these protocols is resource intensive. For example, the use of TCP requires that state information be maintained for each LDP session that is established.
The resource requirements of pseudowire configuration are not a significant concern to service providers when the number of pseudowires is small. However, the use of pseudowires to connect customer edge devices to service provider edge devices is causing more and more demand for pseudowires. As the demand for pseudowires increases, the resource requirements for pseudowire configuration can become a significant drain on network resources. In view of this, there is a need for an efficient and scalable way to configure pseudowires, especially between customer edge devices and service provider edge devices.